Pneumatic dimension gages



April 14, 1959 Simo 2, 1 2 v Y PNEUMATIC DIMENSION GAGES Fil ed Nov. 15, .1955

. INVENTOR 60km 3 A/aafe ATTORNEY K United States Patent PNEUMATIC DIMENSION GAGES Coleman B. Moore, Uwchland, Pa., assignor to Moore Products Co., Philadelphia, Pa., a corporation of Penn- This invention relates to pneumatic dimension gages, and more particularly to an improved gage of simplified construction.

Pneumatic gages have heretofore been proposed, operating upon the principle that if a fluid under constant pressure is forced through upstream and downstream orifices in series with one another, the gaseous pressure in the space between the orifices will be a function of the relative sections of the orifices, and the measurement of the gaseous pressure in the space will indicate the effective area of the discharge or downstream orifice, as varied by the position of the work with respect thereto, within certain limits.

Ithas also heretofore been proposed to interpose a lever or the like, between the nozzle and the work to be gaged. The pivotal mountings heretofore proposed were not wholly satisfactory and cantilever supports also had objectionable characteristics.

I In accordance with the present invention an improved gaging element is provided which is simple in construction, can be quickly assembled and disassembled for access to the gaging nozzle, can have any desired amplification, has a movable leaf as a component part which is exceedingly rugged and not likely to be damaged or injured, has an improved pivotal mounting for the leaf which is completely protected from forces applied thereon in any direction, which does not require close tolerances as between the leaf and the pivot, and in which the leaf is held in position for action in an improved manner.

'Other advantageous features of the invention will be apparent from the specification and claims.

The nature and characteristic features of the invention will be more readily understood from the following description taken in connection with the accompanying drawings forming part thereof, in which:

Figure 1 is a diagrammatic view of a pneumatic dimensiongage in accordance with the present invention;

Fig. 2 is a side view partly in elevation and partly in section of a gage head or plug unit employed in connection with the invention;

Fig; 3 is a view as seen from the top of Fig. 2 with the'cover plate removed;

-"Fi'g. 4 is a fragmentary view as seen from the top of Fig. 2 with both the cover plate and leaf removed;

Fig. 5 is a fragmentary horizontal sectional view, enlarged, showing the pivot and pivot pin for the leaf;

"Fig. 6 is an end elevational view as seen from fli" right of- Fig. 2;

Fig. 7 isa transverse sectional view taken approximately on the line 7-7 of Fig. 2; and

Fig. 8 is a transverse sectional view taken approximately on the line 88 of Fig. 2.

' It should, of course, be understood that the description anddrawings herein are illustrative merely, and that various modifications and changes can be made in the structure disclosed without departing from the spirit of the invention.

Like numerals refer to like parts throughout the several views.

Referring now more particularly to Fig. 1 of the drawings, a pneumatic comparator gage is there illustrated having a fluid supply connection 10 in communication with any suitable source of filtered fluid, such as air, under pressure, which is connected through an adjustable fluid pressure regulator 11 for supplying fluid under constant pressure, and at a selected pressure level, from the supply connection 10. The pressure regulator 11 is connected by a conduit 12 through a restriction 13 which may, if desired, be a fixed restriction, a manually adjustable restriction, or may, if desired, be a variable restriction of the type shown in my prior patent, No. 2,486,052, issued October 25, 1949. The restriction 13 is preferably connected to a conduit 14 having an instrument connection 15 in communication therewith. The instrument connection 15 may be connected to any desired instrument I, for indicating, recording, or controlling, and for purposes of illustration this is indicated as a pressure gage of the Bourdon dial type with a visible face 16 and a movable indicator pointer 17 for ascertaining the pressure conditions prevailing in the conduit 14.

The conduit 14 is in communication with a gaging unit 20 shown in more detail in Figs. 2 to 8, inclusive.

While the gaging unit 20 is shown in a particular position, as will hereinafter appear it can be used in any desired position, including that shown, inverted from that shown, on either side, pointed down or pointed up, or inclined from any of these positions. The gaging unit 20 preferably includes an elongated body portion 21 having a groove 22 along one face thereof, the groove 22 being bounded by an elongated fiat face 23 and spaced side walls 24.

The body portion 21 can if desired have spaced parallel exterior faces 26. The body portion 21 can be provided with one or more openings 27 for the reception of mounting bolts (not shown) for securing the gaging unit at the desired location.

The groove 22 is provided, intermediate its ends, with a transversely disposed pivot pin 30 inserted therein, extending above the face 23 of the groove 22 and terminating at the side faces 26. While any desired type of pin 30 can be employed, it has been found that a pin 30 having spaced cylindrical portions 31 of a predetermined diameter internally disposed in the groove 22, with an interposed cylindrical portion 32, of reduced diameter, functions satisfactorily, as hereinafter explained.

The body portion 21 has a fluid connection 33 extending therefrom to which the conduit 14 is connected and has an interior passageway 34 providing a nozzle which extends normal to and terminates at the face 23 and in predetermined spaced relation, longitudinally considered, with respect to the pin 30.

It will be noted that the nozzle 34 has a fiat surface extending outwardly from it, consisting of a contiguous section of the face 23, and disposed for an appreciable and major portion of the circumference of the nozzle 34. This section of the face 23 extends from the nozzle for a distance of at least several times the diameter of the nozzle 34 to provide a venturi or suction eifect as hereinafter referred to. Interposed between the pin 30 and the nozzle 34, and also extending to and across the face 23, a discharge opening 35 is provided which also extends to the side faces 26 of the body portion 21.

A leaf 46 is provided, which forms the movable portion of the gage unit and is preferably made of a strip of relatively stiff material.

to provide a pivotal mounting by its engagement on the Patented Apr. 14, 1959 The leaf 40 has a short end 7 section 41, a long end section 42 disposed in a plane at' portions 31 of the pin 30. The long end section 42 of the leaf 40 preferably is provided with a contacting button or projection 44, for engagement with the work to be. gaged, soldered or otherwise secured. thereto at the desired location in accordance with the amplification desired. The contacting. projection 44 is preferably of ultra hard material so that, upon repeated engagement with the work, wear will be kept to a minimum.

A cover plate 45 is provided, extending from one end off the body portion 21 to a location spaced from the other end so as not to interfere with the. desired move ment. of the leaf 40, and is secured in position by a screw 4,6v which passes through a relatively large clearance hole 47 provided in the. long end sectionv 42 of the leaf 40. Thecover plate 45 serves to retain the leaf 40. in position when gaging fluid is. not flowing and, also, tends. to protect the leaf 40 and pivot pin 30 from mechanical damage from externalobjects.

The mode of operation. will now be pointed out. g

If no fluid is supplied through the. supply connection 10, or if for any other reason no fluid is supplied to the nozzle 34, the leaf 40 will be retained in the groove 22 by the cover plate 45 in whatever position the body portion 21 is mounted. The leaf 40 will not necessarily have the. section 43 seated on the-pin 30 in the absence of fluid flow.

If pressure fluid is. supplied through the nozzle 34, such fluid will impinge on the inner face of the short end section 41, spread sidewise in such a manner as to provide a venturi action. or suction efiect on this inner face,

and tend to draw the short end section 41 towards the face 23, as permitted by the engagement of the pivot portion.43. with the pin 30. If the section 43 is not properly seated this venturi action tends to cause such a seating.

Ifnow, the long end section 42 is moved towards the face 23 by the engagement of. the work to be measured with the contacting button 44 and to an extent determined by the dimension of the work to be gaged, the space between the inner face of the end section 41 and the face 23 at the nozzle 34 will be varied and the area for discharge through the nozzle 34 will also be varied. Variation of the latter area will cause a change in the pressure in the space between the restriction 13 and the nozzle 34, and the prevailing pressure in that space can be. observed on or utilized at the instrument I, which instrument, with suitable calibration, can be used for reading dimensions.

With the nozzle 34, end portion 41 and surface 23 functioning in this manner, no restoring spring is necessary to move the leaf 40 nor is any holding structure required for the leaf 40 other than the cover plate 45.

The discharge opening 35 has been found desirable to permit the free discharge of the gaging fluid so that there is no back pressure built up capable of changing the readings upon its own variation.

The magnification is, of course, dependent on the ratio of the length of the lever arm along the long end portion 42 from the contacting projection 44 to the pivot pin 30 to the length. of the lever arm along the short end portion from the pivot pin 30 to the nozzle 34. While any desired ratio can be employed within relatively wide limits, a ratio of the order of 14 to 1 has been found satisfactory, with the length of the short lever arm of the order of one-eighth of an inch and the length. of the long lever arm of the order of one and three-quarters inches.

The V-shaped portion 43 provides bearings on the pin 30 at the portions 31 so that the leaf 40 tends to have a two line contact on each pin portion 31 and is selfaligning.

Avery light force is suitable for actuating the contact button 44 and can be made, if desired, ofthe order of.

two or three grams. Excessive force exerted by the work on the contact button 44 cannot damage the nozzle 34 and,.. although. it: is very light, the. leaf.40. is,. neverthe- 4 less, very rugged, can be readily removed for cleaning. and inspection of the gage, and can even be dropped on the floor without upsetting the calibration.

The gage is particularly useful for gaging dimensions or motions which occur at right angles to the longitudinal axis of the gage unit.

I claim:

1. Pneumatic gaging. apparatus comprising a gaging unit having a body portion with a face thereon, said body portion having a nozzle terminating at said face and withsaid face extending around at least a substantial portion of the nozzle, a pivot pin mounted on said body portion, a leaf member having a portion for engagement with said pivot pin, said leaf member having a portion extending in one direction from said pivot pin in covering relation to said nozzle and the part of said face extending around said nozzle and a portion extending in an opposite direction from said pivot pin, saidlast. leaf portion having a part for engagement with the work to be gaged, said firstleaf portion and said face providing a space therebetween for expansion of gaging fluid from said nozzle for exertion on said first leaf portion of a force towards said faceand in a direction to urge said second leaf portion to. wards the work to be gaged.

2. Pneumatic gaging apparatus comprising a gaging unit having a body portion with aface thereon, said. portion having a nozzle terminating at said faceand with said face extending around at least a substantial portion of the nozzle, a pivot pin mounted on said body portion, a leaf member having a portion for engagement with said pivot pin, said leaf member having a portion extending, in one direction from said pivot pin in covering relation to said nozzle and the part of said face extending around said nozzle and a portion extending in an opposite direction: from said pivot pin, said body portion having a discharge passageway extending to a location on said face between said pivot pin and the terminal of the nozzle, said last leaf portion having a part for engagement with the work tobe gaged, said first leaf portion and said face providing a space therebetween for expansion of gaging fluid from said} nozzle for exertion on said first leaf portion of a. force towards said face and in a direction to urge said second. leaf portion towards the work to be gaged.

3. Pneumatic gaging apparatus comprising a gaging.- unit having a body portion with a face thereon, said body portion having a nozzle terminating at said face and withsaid face extending around at least a substantial portion of the nozzle and for a distance of at least a plurality. of diameters of said nozzle, a pivot pin mounted onsaid body portion and having spaced bearing portions, aleai' member having a V-shaped portion for engagementwithi said bearing portions, said leaf member having. a portios'r extending in one direction from said pivot pin in covering relation to said nozzle and the part ofsaid face extending around said nozzle and a portion extending in an opppsite direction from said pivot pin, said body portion havingia discharge passageway extending to a location on said between said pivot pin and the terminal of said nozzle, said last leaf portion having a part for engagement with? the work to be gaged, said first leaf portion and'said face providing a space therebetween for expansion of gaging fluid from said nozzle for exertion on said first leaf portion of a force towards said face and in a direction to urge second leaf portion towards the work to be gaged, aura cover member for said body portion for retaining said-leaflmember. Y 4. Pneumatic gaging apparatus comprising. a connec tion to a source of fluid under pressure, a fixed part having a gaging nozzle in communication with said connec tion terminating thereon with a face extending'therefroin; a movable member having an actuating portion'for move; ment in response to a dimension of the work to'be gagedi means for urging said actuating portion towards the'wol'k to be gaged, said means including a face on said movable" member extending over and movable with respect tosaid first mentioned face and extending over the terminal of the nozzle, said faces and the space therebetween providing a passageway setting up an attractive force between said faces upon expansion therealong of fluid from said nozzle, and measuring means responsive to the fluid discharge conditions prevailing at said nozzle.

5. Pneumatic gaging apparatus comprising a body member having a connection to a source of fluid under pressure and a gaging nozzle in communication therewith, said nozzle terminating at a face of said body member, said face extending around at least a substantial portion of said nozzle, a leaf member movable with respect to said body member and having an actuating portion for movement in response to a dimension of the work to be gaged, means for urging said actuating portion towards the work to be gaged, said means including a face on said leaf member providing a control portion extending over and movable with respect to said first mentioned face and extending over the terminal of the nozzle, said faces and the space therebetween providing a passageway setting up an attractive force between saidfaces upon expansion therealong of fluid from said nozzle, and measuring means responsive to the fluid discharge conditions prevailing at said nozzle.

6. Pneumatic gaging apparatus as defined in claim 5 in which a pivot pin is provided on said body member, and said leaf member intermediate its said control and actuating portions has a portion for tangential linear engagement with said pivot pin at spaced circumferential locations on said pivot pin.

7. Pneumatic gaging apparatus as defined in claim 5 in which a pivot pin is provided on said body member, said leaf member intermediate its control and actuating portions has a pivotal mounting portion in engagement with said pivot pin, and said pivot pin is disposed wholly on one side of said leaf member.

8. Pneumatic gaging apparatus as defined in claim 5 in which a pivot pin is provided on said body and said pivot pin has longitudinally spaced bearing portions and said leaf member has a V-shaped portion intermediate its control and actuating portions for rocking engagement with said bearing portions of said pivot pin.

9. Pneumatic gaging apparatus as defined in claim 5 in which a pivot pin is provided on said body member for engagement by said leaf member and a discharge passageway is provided in said body member extending to a location between said pivot pin and the terminal of the nozzle.

References Cited in the file of this patent UNITED STATES PATENTS 2,478,391 Segerstad Aug. 9, 1949 2,538,622 Johnson Jan. 16, 1951 2,574,342 Mennesson Nov. 6, 1951 2,590,170 Gates Mar. 25, 1952 2,623,294 Fox Dec. 30, 1952 2,712,181 Mahlmeister July 5, 1955 2,802,276 Straw Aug. 13, 1957 

